基于计划评审技术的生产进度评估方法

摘要

An evaluation method for a production schedule under the effect of uncertainties is proposed based on program evaluation and review technique.This method decomposes the working duration into two parts which are ideal planed working time and delayed time caused by uncertainties.The uncertainties are identified and the delayed time caused by the uncertainties is regarded as random variable accordance with the distribution of βand then three -time estimation is conduct to it.Then with the two are added together, the subsequent steps of the production schedule evaluation based on program evaluation and review technique are continued.Examples show that parameters such as the expected duration of each path, variance and the probability of finishing on time obtained by this method and software simulation can quantize the effect of uncertainties to production schedule,providing a basis for production schedule.%为了量化分析生产过程中不确定因素带来的影响，提出基于计划评审技术（PERT）的不确定因素影响下的生产进度评估方法。该方法将工作持续时间分解为理想工作计划时间与不确定因素导致延误时间；对影响生产进度的不确定因素进行识别，将不确定因素对工作造成的延误时间看作符合β分布的随机变量，对其进行三时估计，二者相加后继续经典计划评审技术生产进度评估流程后续步骤。实例表明，运用此方法并借助软件仿真获得不确定因素影响下的各路径工期期望、方差及按时完工概率等参数，可以量化不确定因素对生产进度的影响大小，为生产进度控制提供了依据。